# Replication Package: Japanification — Demographics and Secular Stagnation Risk

## Overview
This folder contains all files needed to replicate the analysis in "Japanification: Demographics and Secular Stagnation Risk." The paper finds that demographics weakly predict Japanification, with highly unstable results across time and income groups. A confirmed structural break shows pre-GFC significance (all Z p<0.01) but post-GFC collapse. The effect is driven by middle-income countries (~$8K GDP/capita), not rich aging economies.

## Requirements
- Python 3.10+
- pandas, numpy, scipy, statsmodels
- Data files in data/processed/

## Structure
- `scripts/` — Analysis scripts (run in phase order)
- `src/` — Shared modules (PanelGLS estimator, data loading, country classifications)
- `data/processed/` — Processed panel data (japan_panel.csv, japan_panel_clean.csv, japan_panel_indexed.csv)
- `output/tables/` — Generated output tables
- `paper/` — Paper manuscript and references

## Reproduction
Run scripts in numerical phase order:
```
python scripts/phase1_data_assembly.py
python scripts/phase2_index_construction.py
python scripts/phase3_panel_estimation.py
python scripts/phase4_channels.py
python scripts/phase5_projections.py
python scripts/phase6_structural_break.py
...
```

## Data Sources
- UN World Population Prospects 2024
- IMF World Economic Outlook
- Penn World Table 10.01
- Chinn-Ito KAOPEN Index
- Lane & Milesi-Ferretti External Wealth of Nations

## Notes
- All analysis uses the 140-country expanded panel (EBA-49 + SSA-20 + EU expansion + Tier 1 expansion)
- The `src/` modules are from the multilateral/followup project and contain the expanded country lists
- Working-age share controls eliminate 93% of signal (demographic dividend ending)
- OADR threshold at 15%; life expectancy turning point ~61 years
- 14/24 economies projected to exceed Japan ~2000 level by 2050
